Operating Systems and File Management
Operating Systems and File Management covers what an operating system does, how it manages processes and memory, and how files and folders are named, located and protected. Board questions favour function lists, operating-system type matching, and path or file-size reasoning.
Core functions
Process management (create, schedule, terminate), memory management (allocation, virtual memory, paging), file management, device management through drivers, and security with user accounts. The kernel runs in privileged mode; the shell or GUI is the user interface.
Types of operating system
Batch systems group jobs with no interaction. Multiprogramming keeps several jobs in memory so the CPU stays busy. Time-sharing switches rapidly to give each user a time slice. Real-time systems are deadline-bound and used in control applications. Distributed systems make several networked machines appear as one.
Files and paths
A file has a name, extension, location, size and attributes such as read-only, hidden and archive. An absolute path starts at the root; a relative path starts at the current directory. A single dot means the current directory and two dots mean its parent. FAT32, NTFS and ext4 are file systems that track where blocks of a file live.
Worked example. The current directory is C:\School\CS and a command opens ..\Notes\unit1.txt. The two dots move up to C:\School, then the path enters Notes, so the file is C:\School\Notes\unit1.txt. Reasoning: only the two-dot segment changes the directory; the remaining segments are appended to it.
Traps. Changing an extension does not convert a file's format. Cut-and-paste moves a file on the same drive but copies across drives. A hidden file is not protected. Deleting to the Recycle Bin is reversible; Shift+Delete is not.